A tube of the above kind is known from DE 297 07 144 U1. There, a binocular tube for a surgical microscope is described. The tube has three housing parts through which the imaging beam path is guided and these housing parts are connected to each other by two rotational joints in a pivotably movable manner. The tube contains a first adjustable mirror element and a second adjustable mirror element. The mirror elements are mounted in the rotational axes of the rotational joints and direct the imaging beam path to the oculars of the tube. The imaging beam path enters via a tube lens having positive refractive power.